Mercury pump



June 13, 1950 w. c. GARDINER 2,511,466

MERCURY PUMP Original Filed Sept. 16, 1947 FIG.I

L INVENTOR WlLLlAM c. GARDINER ATTORNEYS Patented June 13, 1950 MERCURY PUIMP William 0. Gardiner, Niagara Falls, N. Y., as-

signor to Mathieson Chemical Corporation, New York, N. Y., a; corporation of Virginia Continuation of application Serial No. 774,193, September 16, 1947. This application June 4,

1949, Serial No. 97,149

2 Claims. (o1; 103-96) My invention is concerned with lifting mercury (which term I use to include liquid amalgams as well as pure mercury) over relatively small elevations such, for example, as those encountered in the operation of mercury cathode electrolytic cells for the production of chlorine and caustia' To this end, my invention provides an improved mercury pump.

Agitation of an amalgam, mercury containing a dissolved metal, in contact with air tends to oxidize the dissolved metal and thus to form an oxide scum on the mercury. Excessive oxidation may cause the mercury to lose, in large part, its continuous liquid character. In fact, excessive agitation and consequent oxidation may cause the mercury to separate into a granular mass of discrete particles, as contrasted with a continuous liquid body, that is diiiicult if not impossible to pump in any conventional apparatus. For this reason, a mercury pump should operate with a minimum of such oxidation, should have large openings, and should be easily cleaned.

Such a mercury pump is described in United States Letters Patent No. 2,301,722 granted to Charles F. Vaughn. The pump there described comprises a chamber having an annular wall symmetrical about a vertical axis through the chamber, a supply connection to the lower part of the chamber and an overflow discharge connection adjacent the upper rim of the wall, and a an impeller revolving around that axis having substantially the shape of the lower portion of the interior of the chamber. In operation, revolution oi the impeller changes the configuration of the upper surface of the body of mercury in the chamber to a paraboloid of revolution so that mercury supplied to the lower part of the chamber overflows the upper rim of the wall. The mercury within the chamber revolves at substantially the same speed as the impeller and, by limiting the speed of revolution so that the upper surface of the mercury remains unbroken, serious agitation of the mercury is avoided.

By superimposing a body of water on the body of mercury in the chamber of such a pump, I can treat the mercury much more violently within the pump chamber without causing separation of discrete particles, and I can substantially increase the speed of revolution of the impeller and can extend the top of the impeller to the level of the upper rim of the annular wall without encountering difiiculties such as those previously mentioned. I thus secure several advantages, all reflected in a saving in the quantity of mercury required. Less mercury is required for operation of a given pump chamber. The same lift can be effected with a smaller pump chamber..

The mercury pump of my invention comprises a closed stationary chamber having an annular wall symmetrical about a vertical axis through the chamber, an inlet opening for mercury at the lower portion of said chamber, a trapped discharge opening for discharging mercury from the chamber, a blade impeller rotatably mounted on an upright axis having an exterior edgeshape substantially the shape of the vertical cross-section of the annular wall, the upper edge of the annular wall forming a rim over which the mercury flows due to its rotation by the impeller, an enclosed space above the chamber in which the rim of the wall is located, and means for supplying water to and discharging water from the space to maintain water in contact with the mercury overflowing the rim.

In operation, a body of water is maintained over the surface of the mercury in the pump chamber while the mercury is revolved by the impeller at a speed sufficient to overflow, over the rim of the annular wall around the impeller, mercury supplied to the lower end of the pump chamber.

I have illustrated advantageous embodiments of the mercury pump of my invention in the accompanying drawings, in which:

Fig. 1 is a, diagrammatic elevation in section with parts broken away;

Fig. 2 is a top view of the impeller of Fig. 1, and

Fig. 3 is a top view of a modified form of impeller.

, The mercury pump illustrated in the drawings comprises an annular wall symmetrical about a vertical axis defining a bowl constituting the lower part of the pump chamber. The impeller blade 2 of Figs. 1 and 2 is formed of a flat plate having an exterior edge-shape substantially the shape of the vertical cross-section of the annular wall, that is the bowl. The impeller plate is attached to the upright shaft 3 which is rotatably mounted in the bearing stuffing box 4 attached to the cover 5. The wall I is inserted through and attached to the floor 6 which is attached to the upright annular side I to which the cover 5 is removably attached. The floor is extended to one side to form a discharge connection 8 in the form of a trough for the discharge of mercury flowing under the trap 9, The floor 6, Wall E and cover 5 enclose a space it into which water is supplied by pipe II and discharged by pipe l2. Rotation of the impeller causes the mercury to rotate in the bowl I and to travel an upward course as shown by the contour line 13 and overflow the rim l4 into space I!) from which it flows under the trap 9 -:and through gtheydischargezconnection 8.

The pump impeller illustrated in Fig. 3 comprises a plurality of blades l5 mounted on the shaft is and having an exterior edge-shapexsi-milar to the impeller of Fig. 1. The blades are preferably disposed radially and symmetrically about the axis of rotation.

The pressure on the water filling the space H) above the mercury should be the minimum required to maintain the body of water-covering the mercury sinc any pressure above this minimum tends to decrease the effective lift of the pump. The Water may contain, for example, dissolved salt or caustic. Any excess of solutes can be eliminated by flushing .water throughthe upper part plication Serial No. 774,193 of September 16, 1947, now abandoned.

I claim:

1. A mercury pump comprising a closed stationary chamber having an annular wall symimetrical about ayertical axisthroughsaid chamber, --asupp1y= connectionfor mercury to the lower part of said chamber, a trapped overflow discharge connection for mercury communicating withxthe interior of said chamber adjacent the upper rim of said Wall, a blade impeller having substantially the shape of the vertical cross-section of said-annular wall revolving around said axis adapted to impart a motion of revolution around said ;axis .to -.mercury within said chamber, a-cover closing said chamber and connections for supplying water to and discharging Water from the space within said chamber beneath said cover and above mercury therein.

2. A mercury pump according to claim 1 which comprises aniimpeller'having a pluralityof. blades radially and symmetrically disposed about the .4 axis.

WILLIAM C. 'GARDINER.

No-references 'cite'cl. 

